Traffic-signal-operating mechanism



Aug. '6, 1929.

c. W. NElLI ET AL TRAFFIC SIGNAL @FEHATING MECHANISM 5' Sheets-Sheet Filed Feb; 12; 1927 c. w. NEILL 51mm. 1,723,061

' TRAFFIC SIGNAL OPERATING MECHANISM Filed Feb; 12, 192'! s Sheets-Sheet I 2 j 'Aug. 6, l92'9.' c. w. NEILL ET AL 1, 9

' TRAFFIC SIGNAL OPERATING. MECHANISM Filed Feb. 12, 1927 I 5 Sheets-Sheet 3 8/5/1 11 flo/derfioa/ Rider 2 e3 cam 3 25 Riderl a6 Down am J6 'UpCam 34 4-40 4-50 5-0 am 520 530 5-4.0 760 run-sec 250 290 300 am 329 we 40 s50 aeo sec- Elm/04244136 6 Aug. 6, 1929. c. w. NEILL ET AL TRAFFIC S IGNAL OPERATING MECHANISM Filed Feb. 12, 1927 D1 STonce KM 26x 60 u leobm Crox lTrbff/c Q, v G

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Aug". 6, 1929. c.-w"NE|LL ET AL vB 9 mRAFFIq-sIGNAL OFIEVRATYIJNG MECHANISM I Filed Feb. 12, 1927 -5 Sheets-Sheet 5 5m ST.

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(3 Top G glwve ntou Patented Aug. 6, 1929.

UNITED STATES PATENT OFFICE.

CHARLES W. NEILL AND T HOMAS NEILL, OF WASHINGTON, DISTRICT COLUMBIA.

TRAFFIC-SIGNAL-OPERATIN G MECHANISM.

Application filed February 12, 1927. Serial No. 167,711.

Our invention relates to automatic traffic signals. lVhere there are a number of adjacent busy street intersections it is common to-employ automatic signals at each of these.intersections to direct the traffic.

1 These signals are operated by electricity so that their indications all change at the same time at predetermined intervals which are controlled by a central timing device. B

having the signal indications at alternate intersections different and the period hetwcen changes equal to the time required for a Vehicle to run from one intersection to the next, non-stop traffic may be obtained.

- The signal indication in effect progresses'up and down the street ahead of the traffic which it directs. An improved non-stop system of directing street traffic based in this idea of progressive movement is described in our co-pending application, Serial No. 45,334, filed July 22, 1925. The object of this invention is to provide mechanical-means for operating automatic signals according to the method of directing street traffic described in said co-pending application or I according toany other method of directing, based on the progressive movement of the traffic. A further object is tq provide certain improvements in the system described in said co-pending application Serial No. 45,- 334. One outstanding difference between the invention shown in this application and that shown in said application N 0. 45,334 is in the number of traffic. showed separate sets of signals for directing up traffic, for di'rc6ting down traffic, and for directing cross traffic. the invention in application No. 45,334 was not limited to three separate sets of signals the. en'lhodiment shown and described had three sets. In this application the embodiment of the invention shown has only one set of signals for bothup and down highwaytraffic and cross street traffic. The reasonthis improvement is that the cross street linust be closed it the intersection is opcnito eithenup or down highway traffic, and with the cross traffic stopped it appears advantageous,r in*most cases, to indicate Go signals used to direct source .and operate at In our application No. 45,334 we- Although broadly to traffic from both directions on the highway.

The advantages of the mechanism hereinafter described are that it provides for independent operating mechanism at each intersection, all of which operating mechanisms are driven by power from a central the same speed. These signal operatingmechanisms maybe set in relation to one another so .that the signal indications directingthe traffic Will progress from one intersection to another atany desired rate of speed independent of block lengths and at the sametime the ratio of intervals during which any intersection I is open to up-down and to cross traffic when taken over the whole cycle, may be whatever, is desired for that particular intersection. Other objects and advantages will be ap-. parent as the description proceeds. j

The operating mechanism is illustrated in the accompanylng drawings in-which,

Fig. 1 is a View of three intersection signals wired to their operating mechanisms. A side view of one of the operating mechanisms is shown in large scale?" Fig. 2 is a front view of the operating mechanism shown in Fig. 1 in large scale.

Fig. 2 isa detail side view. partly in section, of a brush, holder and switchboard.

Fig. 2 is a detail view of a brush and holder viewed from the switch boardside.

Fig. 3 is a top view of the operating mechanism. K Fig. 4 is a displacement diagram illustrating. the movement of the brushes over the switch board contacts. 1 '1 Fig. 5 is a graphon time-distance coordinates, illustrating the signal changes in the signal lights shown in Fig. 1.

Fig. 6 is a wiring diagram of the switch board of an o crating mechanism to the signal lights w lich it-operates. j

' 0n time-distance coordi- Fig. 7 is a graph I nates illustrating the signal changes in the signal lights in a simplified-modification of, the mechanism. v v

Fig. 8 is a wiring'diagram of the switch board to produce the results shown in Fig. 7

Fig. 1 shows traffic si nal towers 1, 2, and 3, which are located at t eir respective street shown will, when lit, indicate Go and Stop respectively thru bulls eyes at right angles to the ones shown. 'The signal towers 1', 2, and 3 are wired to their operating mechanisms 4, 5, and 6 respectively The wiring will be described in connection with Fig. 6.

. A power line 7 runs the length of the street and connects to the motor of the operating mechanism at each intersection.

The motor which drives the operating mechanism consists of a solenoid 10 mounted on a frame 11. Periodic power impulses are sentthru power line 7 and these impulses excite solenoid 10 causing it to pull iron plug 12 against the adjustable brass stop screw 13.

Attached to the lower end of the iron plug 12 is a support bar 14 (see Figs. 1 and 3) to which are attached pawls 15. These pawls 15 are heldby springs -16'against-ratchets 17 which are rigidly connected to cams 18. Each ratchet cam assembly is free to turn on shaft 19 independently of the other ratchet cam assemblies, but in the normal operationof the mechanism the support bar 14 moves all of the pawls 15 at the same time so that each ratchet is advanced the distance of one tooth.

The iron plug 12 is drawn up againststop screw 13 when solenoid 10 is excited and when the magnetism dies down the iron plug drops back by gravity to the position shown in Fig 1.

If stop screw 13 is set sothat the length of stroke of iron plug 12 is greater than the length of one ratchet tooth but less than the length of two, then with every power impulse each ratchet and its attached cam will be turned thru an angle equal to 360 No. of teeth a I k I I 0 a and if the solenoid receives one power 11npulse per second each ratchet will turn with its cam at a speed of ".No. of teeth v 60. R. P. M. Thus byv having a different number of teeth. on the ratchets, the solenoid motor will drive the cams at different speeds.

It is important that the cam ratchet assemas those, 0 another ratchet, these teeth would vbe so small that the ratchet would be turned thru an angle of two teeth by a stroke of the pawl which was long enough to take one tooth of, the other ratchet.

I five each.

intersections. The Stop and Go signals a Each cam 18 has a roller follower 22 attached toa rocker arm 23. Said rocker arms are carried by a shaft 24 (see Figs. 1, 2, and 3).

Referring to Fig. 1 it will be noted that rocker arm 23 operates a brush holder rod 25 which has a yoke 26 at its lower end Which fits over the rocker arm. Above the .middle of the brush holder rod 25, is a brush holder 27 from which projects a brush 28 which operates over a switch board 29. Fig. 2" shows. in detail the way in which the brush 28 is held against the contacts on the switch board by a spring 52.

Referring to Fig. 2 it will be noted that there are 3 rocker arms each one operating its .own brush holder rod. These brush ,holder rods are numbered 25, 34 and 36 (Figs 2 and 3) and are free to move up and down in bearing pieces 30 and'31.

There are twenty-five contact points on the switch board arranged in five rows of Most of these contacts are shown in dotted lines in Fig. 2. A cable 32 (see Fig. 1) containing-wires for each signal light connects the switch board contacts with the signal lights. This wiring will be fully explained in connection with Fig. 6.

Between brush holder rods 34 and 36 (see Fig. 2) there is located a rider brush holder rod which is similar to the other brush holder rods described except that it is shorter and instead of a yoke at the lower end has attached to it a cross member which is in the form of a yoke at both ends so as to straddle the brush holder rods 34 and 36. \Vhen the brush holder rod 34 rises, a pin "47 which projects from it strikes against the cross member 45 and causes the rider brush-holder rod 35 -to rise also. Brush holder rod 36 may also cause rider brush holder rod 35 to rise the pin 48 being provided for this purpose. Rider brush holder rod 35 will be forced to rise, therefore, against the tension of the spring shown,

if the brush holder rod on either side of it rises.

A rider brush holder rod 33 is mounted between the brush holder rods 25 and 34. A cross member 44 connects to the lower end of this rider brush holder rod. This cross member has yoke ends which straddle the brush holder rods 25 and 34. A spring 49 connected to an extension member 50 pulls rider brush holder rod 33 in a raised position, but if either brush holder rod '25 or rider brush holder rod 35 are in a low position the pin 46 or cross members 45, respec- "tively, will hold cross member 44 and its attached rider brush holder rod in a low position. It is obvious that the springs holding brush holder rod 25 and rider brush holder rod 35 down, must be stronger than the spring holding rider, brush holder rod 33 in a raised position. The movement of the brush holder rods will be discussed further in connection with Fig. 4.

The switch board 29 is of any smooth insulating material and has twenty-five contacts mounted in it so as to be flush with the surface of it as shown in Fig. 2 The reason a for having twenty-five contacts is to obtain a uniform block. There are many ways of wiring the switch board. In no case will all of the twenty-five contacts be necessary, but the use of this block having the full number seems desirable both for uniformity in manufacture and to avoid the necessity of a new block if the method of wiring is changed. The source of power for the signal lights connects with the frame of the machine and each brush therefore closes the circuit to a signal light whenever it touches a contact on the switch board which. is wired to a light. The wiring of the switch board to the lights is shown in Fig. 6. It will be noted that with the method of wiring the switch board used in Fig. 6'there are a number of contacts which are not used.

. When the brush holder rods are in certain positions it is desirable to hold rider brush holder rod at the top position even the brush holder rods 34 and 36 are in a lower position. And it is sometimes desirable to hold rider brush holder rod 33 in its lowest position even tho brush holder rod 25 and rider brush holder rod 35 are in a higher position. To accomplish this result magnets 42 and 43 are mounted as shown in Figs. 1

and 2. A magnetextension piece 40 attached to cross member 45 of rider brush holder rod 35, strikes against the core of magnet 42 when the brush in rider brush holder rod 35 is on the top contact of the switch board. A. magnet extension piece 41 attached to cross member 44 of rider brush holder rod 31 strikes against the core of magnet 43 when the brush in rider brush holder rod 33 is on the second contact from the bottom. Thus the bottom contact is never touched by this brush or by the brushes in brush holder rod 25 and rider brush holder rod 35. It will be noted in the wiring diagram that these contacts are not used. 7

Fig. 4 shows displacement diagrams for the brushes. Five displacement diagrams are shown and they can best be understood by considering Fig; 4 in connection with Fig. 2.

The lowest of the displacement diagrams is marked Up cam and shows the length of time that the brush in brush holder rod 34 remains on each ofits five contacts and the time of change. It will be noted that the cam operating this brush makes one rev olution in '70seconds.

The second displacement diagram is marked Down cam .and shows the length of time that the brush in brush holde'rrod height as the higher of 36 remains on each oi its five contacts and the time of change. The cam operating this brush makes one revolution in 56 seconds.

The third displacement diagram shows the changes in the brush positions of the brush in rider brush holderrod 35. This brush never comes below the second contact since in this position cross member 45 is stopped by cross member 44; otherwise this rider brush occupies the contact at the same the brushes on either side of it, that is, the brushes in brush holder rods 34 and 36.

The displacement diagram for the brush in brush holder rod 25 is marked Cam 3. This cam makes one revolution in 56 seconds.

The movement of rider brush 2, which is the brush in rider brush holder rod 33 depends on the movement of brush holder rod 25 and rider brush holder rod '35. Rider brush 2 is pushed down by whichever of its operating brush holder rods is the lowest, that is, brush holder rod 25, or rider brush holder rod 35.

lVith-the switch board wired as shown in Fig. 6 and with cams having the displacement diagrams shown in 42 and 43 ,wili hold their respective crider brush holder rods so as to prevent a Go signal indication from being given to cross traffic where the period would not be longer than 10 seconds as will be more fully explained in connection with the description of the complete operation of the machine. Cams to give other minimum periods could be used. The wiring diagrams (Figs. 6 and 8) make it obvious what combination of positions the brushes must occupy in order to have the magnets 42 and 43 operate. Unless the rider brush holder rod is on the contact nearest its magnet so that its magnet extension piece is touching the core of the magnet, the magnet upon being excited will hasl e no efiecct on the rider brush holder ro s.

Fig. 5 shows a time-distance graph of the operation of the signal lights using operating mechanism as above described to operate the lights at the F Street intersection and with modifications at the intersections of G Street and of H Street.

Fig. 6 shows wiring diagram of the contact board. The brush holder rods that operate over the rows of contacts are shown at the bottom of the figure,

Referring to Figs. 2 and 6 it will be noted that the only brush that lights the signal lights is the brush in rider brush holder rod 33.

The complete operation of the mechanism Fig. 4 the magnets holder rod 33 down.

The brush,'n holder rod Fig. 4) is operated by holder rods 34 and 36 and will be raised by whichever of these holder rods 34 or 36 is the highest. At the 280 sec. interval in Fig. 4 the brush in holder rod 35 is on its middle contact.

At the 280 sec. interval the brush in holder rod 25 (cam 3 in Fig. 4) is rising toward its top cont-act. Referring to Fig.2 and the wiring diagram in Fig. 6 shows that this movement of the holder rod 25 has no effect on the operation of the other holder rods.

The brush in holder rod 33 (Rider 2 in Fig. 4) is operated by holder rods 25 and 35 and will be lowered by whichever of these holder rods 25 or 35 is the lowest. At the 280 sec. interval in Fig. 4. the brush in holder rod 33 is held down to its middle contact by holder rod '35 and power will be -furnished to magnet 43 as is obvious from the wiring diagram in Fig. 6. The magnet 43 will be excited but will have no effect at this timesince there is no holder rod in contact with the magnet 43.

During the interval from 280 secs. to 290 sees. in Fig. 4 the brushes in holder rods 34 and 36 fall-to their bottom contacts. Refer-. ence to Fig. 6 shows that in this position they close no circuits. Holder rod 35 falls to its lowest position pushing holder rod 33 to its lowest position, into contact with magnet 43 as shown in Fig; 2. It should be noted that this lowest position of holder rod' 33 and also of holder rod 35; puts there brushes on the second to bottom row of contacts. These brushes never fall to the bottom row of contacts. Reference to Fig. 6 shows that the brush in holder rod 33 when it falls to its lowest contact lights theh'ighway go signal. Holder rod 25 on the top contact closes no circuits.

During the interval from 290 secs. to 300 sees. in Fig. 4 holder rod 25 drops to its next to top contact closing the circuit through magnet 43. Magnet 43 is excited and will hold holder rod 33 in its lowest position if holder rod'35 should rise before holder rod 25 falls low enough to itself hold Such a situation requiring magnet 43 to hold holder rod 33 does not occur at this time in Fig. 4 however since holder rod 35 does not rise before holder rod 25 falls through its full travel.

In Fig. 4v at this time both magnet 43 and holder rod 35 are holding holder rod 33 in its lowest position.

During the interval from 300 secs. to 310 secs. in Fig. 4 holder rod 34 rises to its next 3 to bottom contact. A second or two later holder rod 36 takes a similar rise. Each of thesemovements closes a circuit to magnet 42, but holder rod 35 is not in contact with the magnet and the magnet therefore has no effect. It should'be noted that this rise has no effect on holder rod.35 which is the next to bottom contact below already on Holder rod 25 falls which it never falls.

to its middle contact which has no effectand the magnet 43 could not be of any further necessity.

During the interval from 310 secs. to 320 secs. in Fig. 4 holder rod 34 rises to the middle contact pushing holder rod up with itto the middle contact. This closes the circuit to magnet 43 which becomes excited and holds holder rod 33.- This has no effect, however, since holder rod 33 is being held down anyway by holder rod 25. Holder rod 36 also rises to the middle contact during this interval but the movement has no effect.

During the interval from 320 secs. to 330 secs. in Fig. 4 holder rod 34 rises to thetop contact, pushing holder rod 35 to the top contact and into contact with magnet 42. A few seconds later holder rod 36 also rises to the top contact. No circuits are closed by the brushes on the top contacts. Before the end of this interval holder rod 36 falls to the next to ,top contact, but this movement has no efiect. It should be noted that if both holder rods 34 and 36 had fallen at this time to the next to top contact holder rod 35 would also have fallen closing the circuit to magnet 43 which would have held holder rod 33 down in its lowest 1 position even though holder rod 25 should rise. The magnet 43 would thus hold holder rod 33 down until holder rod 35 reached its low position where it would "itself hold holder rod 33 down making the magnet 43 no longer mg spring 49 to, pull holder rod 33 to the top position "thus changing the trafiic signal indication to the, highway stop signal indication and cross trafiic go signal indication.

During the interval from 340 secs. to 350 sees. in Fig. 4. at the beginning of this period holder rod 34 drops to its next to top contact position allowing spring 38 (Fig. 2) to pull holder rods 35 and 33 into the next to top contact position. This has no efiect on the tratlicsignals but closes the circuit signal indication and Riders 1 and 2 will to magnet 43 which at this time has no effect since holder rod 33 is not in contact with the magnet. Toward the end of this interval holder rod 34 drops to its middle contact position allowing spring 38 (Fig. 2) to pull holder rods 35 and 33 into the middle contact positions. This movement of holder rod 33 changes the traffic signal indication to caution.

During the interval from 350 secs. to 360 secs. in Fig. 4;, holder rod 34 drops to its bottom position. Spring 38 (Fig. 2) pulls holder rods 35 and 33 into their lowest positions, which is the next tobottom contact position. This movement of holder rod 33 changes the traiiic signal to the highway go cross trailic'stop signal indication.

Referring to F ig. 4 it will be noted that the Up cam completed a cycle between the 280 sec. and 350 see. time intervals. The Down cam completed a cycle between the 280 sec. and 337 sec. time intervals. The cycle of cam 3 on the mechanism shown was the same as that of the Down cam, though this was not necessary. The positions of depend on the cam positions. The cycle of operation-of Rider 1 will be the least common multiple of the cycles of the Up and Down cams while the cycle of operation of Rider 2 will be the least common multiple of thecycles of cam 3 and Rider 1.

If brush holder rod 25 and the rockerarm, spring, cam. ratchet and pawl operating it are removed and rider brush holder rod 33 and its spring, magnet, cross member, etc. are also removed from the mechanism and the switch board wired as in Fig. 8; the signal lights will be operated as in Fig. 7. Shaded areas represent Go signal indication periods for the trafiic on the street graphed; white areas are crossqtraiiic Go indication periods.

The operation of the mechanism will 'now be shown in -Fig. 4 by the displacement diagrams marked Up cam, Down cam, and Rider 1. The parts giving the other displacement diagrams having been removed from the mechanism. I

Referring to Fig. 8 it will be noted that the brush in holderrod 35 (Rider 1 in Fig. 4) now lights the traflic'signals. The displacement of the brush in holder rod 35 shown in Fig. 4 (Rider 1) shows the changes of the trafiic signal indications.

At the 280 second intcrvah in Fig. 4,

return of the holder rod 35 to the middle contact position.

At the 321 sec. interval holder rod 35 rises to the top position changing the trafiic signal indication to the highway go and cross traiiic stop signal indication.v

At the 340 sec. interval holder rod 35 drops to the next to top contact position. This movement does not change the traflic signal indications but removes holder rod 35 from the influence of magnet 42 with which it is contact when in the top position, as previously described.

At the 34:8 sec. interval holder rod 35 moves down to change the traflic signal indication to caution and at the 351 sec. intervalmoves down to change the traiiic signal indication to the highway go and cross traflic stop signal indication.

The foregoing description taken in connection with the drawings is a complete disclosure of the construction and operation of the signal light operating mechanism. A discussion of the theory of the graphs shown in Figs. 5 and 7 seems unnecessary for the purposes of this specification; The graphs .are made to fit the traliic movements on the street and the cams to be used and the settings of the mechanisms will be determined from the graphs.

-As explained in the first partof the specification, the signal indications to up and down highway traflie are given by means of I the same signal, orwhat may be called a common signal for both up and down traflic on the highway. In Figs. 5 and 7, therefore, the shaded bands which slope to the right represent Go signal indications by the same signal as the Go signal indications represented by the shaded bands which slope to the left. The bands sloping to the right represent Go signal indications which are given for platoons of progressive traflic moving up the highway. While the Go indications given by these right sloping bands are given for up traflic, they also indicate Go to down traflic on the highway. It should be noted however that the down traiiic, crossing an intersection during such a Go indication period, is not in a progres-' sive platoon and may beblocked at the next intersection by a Sto signal indication. The bands sloping to t e leftrepresent Go signal indications for platoons of progressive trafl'ic down the highway. The Go inwhich are not in one of the progressive.

platoons from. that direction, to cross the intersection whenever a progressive platoon from the opposite direction is crossing, is that it will greatly benefit street cars', busses, delivery trucks, and other vehicles which cannot keep in a platoon, or are going only a short distance on the highway. 1

The operating mechanisms are set from the aphs, for example the cam-or cams, that control the Go signal to producethe bands sloping to the right in the graphs, are set back an increased number of ratchet teeth at each intersection up the highway so that the change produced by these cams will occur later at each intersection progressively up the'highway. If the distance between the intersections is short the cam at the next intersection will be set back only a few ratchet teeth. If the distance is long the cam at the next intersectioniwill be set back the? will maintain this setting since allof the cams for producing the shaded bands sloping to the right have the same number of teeth on their driving ratchets, and therefore make the same number of revolutions in a given time. All of the cams for producing the bands sloping to'the left have the same number of teeth on their driving ratchets, but preferably a different number than have the ratchets driving the cams which produce the right sloping bands.

The mechanism described is designed, to give the greatest flexibility-practicable in conforming the operation of the signal lights to the actual traffic conditions at the various corners.

Various modifications of part or all of- -the mechanism may be employed -without departing from the scope of the claims. We claim: 1. In a traffic signal system for directing traffic on a highway intersected by a plurality of cross streets, signals for directing traffic at the intersections, separate control devices for changing the indications of the signals at each intersection, means in said control devices which maybe set in a definite time relation with respect to each other, and forming when operated a progressive signalsystem up the highway; other means in said control devices which may be set in. a definite time relation with respect to each other, and forming when operated a progressive signal system down the highway, a motor for each control device for operating the means of both the up and down systems, all of said motors being operated means for operating said cams independent- -ly of each other, signal change means and connecting means between said cams and signal change means whereby said signal change means may be operated independently by each of said cams or by that cam giving the greater displacement to the connecting means at the time.

3. In a traffic signal device comprising a mechanism for changing a signal indication for directing traffic at a highway intersection, a cam for changing the signal indication for traffic moving in one direction and a second cam for changing the signal indication for traffic moving in another direction, signal changing means operated by said cams for. changing the signal indication for,

traffic moving in a third direction, and means operated by said cams to prevent said signal'change means from operating to change the signal indication for traffic inva third direction when thetime interval between the termination of the signal indication for traffic in the first direction and the beginning of the signal indication for traffic in the second direction is less than a predetermined interval of time.

4. A traflic signal control mechanism for changing signal indications directing traffic at a street intersection, comprising means for controlling ,a traffic signal for traffic from one direction, independent means for controlling' a traffic signal for traffic from another direction, and means under the control of the; first two means for controlling a traffic signal for traffic from a third direction.

5. A traffic signal control mechanism for changing the signal indication directing traffic at a highway intersection, comprising means for controlling the traffic. signal for traffic moving up the highway, independently set means for controlling the traffic signal for traffic movingdown the highway, and means under the control of the first two means for controlling the trafiic signal for traflic on the cross street:

'6. A street traffic signal control mechanism for changing the signal indications di rectmg traflic at a highway intersection, comprising cam means for controlling the signal for traflic moving in one direction along the highway, second cam means for controlling the signal for traflic moving in the opposite direction along the highwa step-by-step mechanism connected with said cam means, means for operating said cam means through said step-by-step mechanism, and means under the control of both of said cam means for controlling the signal for tratfic on the cross street.

7. A street traffic signal control mechanism for changing the signal indications directing trafiic at a highway intersection, comprising arfirst cam means for controlling the signal for traffic from one direction along the highway; a second cam means for controlling the signal for traffic from the opposit'e direction along the highway; step-bystep mechanism connected with said first cam means; otherv step-by-step mechanism connected with said second cam means; means for operating said cam means through said step-by-step mechanisms; and means under the control of both of said cam means for controlling the signal for traffic on the cross street.

8. A street traflic signal control mechanism for changing the signal indications directing tra'iiic at a highway intersection, comprising a first cam means for controlling the signal for trafiic from one direction along the highway; a second cam means for controlling the signal for traflic from the opposite direction along the highway; step-bystep mechanism connected with said first cam means; other step-by-step mechanism connected with said second cam means; an electric motor for operating both ,of said cam means through said step-by-step mechanisms; and means under the control of both of saidcam means for controlling the signal for traffic on the cross street.

9. A trafiic signal control mechanism for changing the signal indications directing traffic at a highway intersection, comprising a first cam means for controlling the signal for trafiic from one direction along the highway; a second cam means for controlling the signal for traiiic from the oppositedirection along the ,highway; step-by-step mechanism comprising pawl and ratchet mechanism, connected with said first cam means; other step-by-step mechanism com prising pawl and ratchet mechanism; connected with said second cam means; an electric impulse motor for; operating said pawl means to drive saidratchet means; and means under, the control of both of said cam means for controlling the signal for tratlic on the cross street.

' 10. A traflic signal control mecl amsm for changing signal indications directing traflic signals for the cross street; signal control -means for each intersection including means for cyclicly causing a highway go signal indication and independently set means for also cyclicly causing a highway go signal indication,.both of said highway go signal indications being given by means of the same signal; and means for causing a cross tratiic go signal indication at intervals when neither of said first mentioned means is causing a highway go signal indication; mechanism for operating said signal control means including motor means and driving means between the motor and signal control means for each intersection, said driving means including mechanism by which the signal control means for each intersection may he set independently of the controlling means for any other intersection.

12. In a street trafiic signal'system, signal stations spaced along a highway for directing traflic at intersections, Stop and Go signals at each signal station for directing highway trafiic, Stop and Go signals for directing cross trafiic, control mechanism for each signal station for cyclicly changing the signal indications for up traific on the highway, independent of the corresponding control mechanism for the other signal stations, so that it may be set with relation to the corresponding control mechanisms of the othersignal stations, to cause, when operated, a Go signal indication to progress ahead of traffic moving up the highway; and control mechanism for each signal station for cyclicly changing signal indications for down trafiic on the highway, independent of the corresponding control mechanism for the other signal stations, so that it may beset with relation to the corresponding control mechanisms of the other signal stations, to cause, when operated, a Go signal indication to progress ahead of traflic moving down the highway, the same Go signal directing both up and down highway tratfic; and means operated by both said u trafiic signal control mechanism and said own tratiic signal control mechanism to change/the signal indications for cross 0 I trafiic; and means for operating said control means n unison.

13. In a signallin'gs'ystem for regulating trailic on a highway intersected by a pl ural ity of cross streets, signal means for directing traiiic at the intersections comprising'Go and Stop signals for signalling trailic moving in opposite directions along the highway, and Go and Stop signals for signalling cross street trailic, means for controlling said signals for causing groups of Go signal indications to appear to move in one direction along the highway, controlling said signals for causing Go signal indications to appear to move along the highway in the opposite direction, and so as tocause' the omission of the Go signal indication to traiiic on the highway at recurring intervals of time, at any intersection, and for causing the highway Stop signal indication and cross tratiic Go signal iiulication-to be given during that interval, at thatintersection, and for causing the cross street Stop signal indication to be given at all other times mentioned; including separate signal operating mechanism for each intersection along the highway, each operating mechanism in cluding separate means for controlling the progressive up signal indications and the progressive down signal indications, said separate means controlling the same Go signal for directing both up and down high way traffic, a motor and driving means between the motor and the controlling means, including mechanism by which' the controlling means for each signal may be set independently of the controlling means forany other signal.

14. In a traflic signal system for regulating traiiic along a highway intersected by a series of cross roads, signal devices at intersections for regulating traffic along the highway and along the cross roads, each of said signal'devices' having Stop and Go signals for directing trafiic moving up and down the highway, and Stop and Go signals for the cross road, separate signal control mechanism for each signal device along the highway for controlling the signals thercat, including a first cam means in each controlling mechanism for changing .the signal indication on the highway, at second cam means in each controlling mechanism, set indopcndently of the first cam means for changing the signal indication on the highway, means for changing the signal indication for trailic on the cross road; a motor for each signal device, driving means between each motor and its corresponding signal controlling mechanism including means by which the controlling mechanism for thatintersect-ion may be set independently of the controlling mechanisms for the otherintersections so that all of the first. cam means may he set with relation to each other to change the signal indications progressively up the highway, and all of the second cam means may be set with relation to each other to change the signal indications progressively down the highway, both of the cam means in each controlling mechanism ch: ng-" ing the indications of the sine highway signal, and means for operating said motors operating the Go signals for traflic from one direction in cycles, and the Go signals for t-rafiic from the other direction in different cycles, and in causing the Go signal indications for traitic from one direction and the Go signal indications for traffic from the opposite direction along the highway to appear progressively in thedirection of the correspoding tratfic in such timed relation that there will be recurring intervals of time, at each intersection, when there is no Go signal indication being given for either up or down highway traffic, and in causing a Go signal indication to cross road tratfic, and Stopsignal indication to highway trafiic, to be given at the intersection during said recurring intervals of time, and in giving the Go signal indication for highway traflic from one direction and the Go signal indication for highway traflic from the opposite direction with the same signal.

16. The method of regulating trafiic on a.

highway intersected by a plurality of cross streets and havin signal units comprising Stop and Go signals for the intersections for signalling trafiic moving up and down the highway and on the cross streets; which method consists in causing the Go signal indication to app-ear at successive signal units progressively up the highway, the Go signal indication of each signal unit to appear after the Go signal indication at the preceding signal unit along the highway, and to persist until after the Go signal indication appears at the next signal unit along the highway, and to be'followed after. a predetermined lcngth of time by a Stop signal indication, and in causing a Go signal indication to' appear at successive signal units progressively down the highway ahead of traffic moving down the highway, and in such timed relation with respect tosaid Go signal indication progressing up the highway that there will be recurring intervals of time at the signal unit for each intersection, when there is no Go signal indication being given to either up or down highway traffic, and in causing a G0 signal indication .to cross street traific to be given at each signal unit during said recurring in a plurality of cross streets, having signals for directing trafiic at the intersections, said signals comprising Go-Stop signals for the highway, and Go-Stop signals for the cross streets; which method consists in causing a Go signal indication to appear at successive signal units progressively up the highway, said Go signal indications at each signal unit being given in cycles, and in causing a Go signal indication to appear at successive signal. units progressively downthe highway, said Go signal indications at each signal' unit being A given in cycles, and in making said first mentioned cycles different from said last mentioned cycles, so that there will be recurring intervals of time at each" signal unit when there is no Go signal indication being given to highway trafiic, and in causing a Go signal indication to be given to cross street traffic and a Stop signal indication to highway traffic during said recurring intervals of time, and in signalling the trafiic from both directions along the highway by means of the same signals.

18. The/method of operating a trafic signalling system, for a highway intersected bya plurality of cross streets, having signals for directing traffic at the intersections, said signals comprising (lo-Stop signals for the highway and- Go-Stop signals for the cross streets; which method'consists in causing a Go signal indication to appear at successive signal units progressively up the highway, said Golsignal indication at each signal unit persisting until after the G0 signal indication appears at thenext succeeding signal unit, and in causing a Go signal indication to appear at successive signal units progressivel down the highway, and in so timing the 0 signal indications which progress up the highway with respect to the Go signal indications which progress down the'high- Way thatthere will be recurring intervals of time at eachsignal unit when there is no Go signal indication bein given to highway traihc, and in causing a (1%) si 91 indication to be given to cross street tra c, and a Stop signal indication to highway traffic, during sa d recurring intervals of time, and in signailing the traflic from both directions alongthe highway by means of the same signals.

19. In a signalling system for regulating .trafiic on a highway intersected by a plurality of cross streets, signals for directing traflic at the intersections, comprising Sto Go sils for the highway, and Stop- 0 signals for the cross streets, means for controlling mid signals .which maybe operated to u e o gnal indications to progress in opposite directions along the highway, and to cause a Stop signal indication to be given to trafiic from both directions on the highway at recurring intervals of time at each intersection, and to cause the cross street Go signal indication to be given during that interval at that intersection, and for causing the cross street Stop signal indication to be given at all other times; said controlling means including separate means for causing the Go signal indications to progress in opposite directions'along the highway, both of said separate means operating the same signal; mechanisms for operating said signal controlling means including motor means and driving means between the motor means and the signal controlling means including mechanism by which the means for causing the Go signal indications to progress in opposite directions may be set independ ently 'of one another.

20. A street traffic signal control mechanism for changing the signals directing traffie at a highway intersection, comprising a pair of cams, step-by-step operating means individual to each cam, and a common motor driving both of said operating means.

'21. A; street trafiic signal control mechanism for changing the signals directing traffic at a highway intersection, comprising a pair of cams, step-by-step operating means vindividual to each cam, teeth on said stepby-step operating means, the teeth on one operating means being longer than the teeth on the other operating means, so that the 3 rates of movement of the two operating means will be different; and a common motor driving both of said operating means.

22. The method of regulating trafiicon a highwayintersected by a plurality of cross streets and having signal units comprising Stop and Go signals for the intersections for signalling 'traflic moving up and down the highway and on the cross streets; which methddconsists in causing the Go signal indication to appear at successive signal units progressively up the highway, the Go sign al'indication of each unit to appear after the Go signal indication at the preceding signal unit along the highway, and to persist until after the Go signal indication appears at the next signal unit along the highway, and to he followed after a predetermined length of time by a Stop signal indication,

and in causing a Go signal indication to appear at successive signal units progressively down thehighway ahead'of trafiic moving down the highway, and in such timed 'relation with respect to said Go signal indication progressing up the highway that there will be recurring intervals of time, which may be of substantially the same total duration, at the signal unit for each intersection, when there is no Go signal indication being given'to either up or down highway trafic.

and in causing a Go signal indication to cross in signalling the traffic from both directions along the highway by means of the same signal. 7

23. The method of operating a traffic signalling system, for a highway intersected by a plurality of cross streets, having signals, for directing trafiic at the intersections, comprising Go-Stop signals for the highway and Go-Stop signals for the cross streets; which method consists in causing a G0 signal indication to appear at successive signal units progressively up the highway, said Go signal indication at each signal unit persisting until after the G0 signal indication appears at the next succeeding signal unit, and in causing,

a G0 signal indication to appear at successive signal units progressively down the highway, and in so timing the Go signal indications which progress up the highway with respect to the G0 signal indications which progress down the highway that there will be recurring intervals of time, which may be of substantially the same total duration, at each signal ,unit, when there is no Go signal indication being given to highway traffic, and in causing a Go signal indication to be given to cross street trafiic, and a Stop signal indication to highway traffic, during said recurring intervals of time, and in signalling the traffic from both directions along the highway by means of the same signals.

In testimony whereof we aflix our signatures.

' CHARLES W. NEILL.

THOMAS NEILL. 

